Method and apparatus for treating garbage and the like waste materials



Aug. 12, 1941. K. PETERSEN File'd March 13, 1939 4 Sheets-Sheet i Aug. 12, 1941.

K. PETERSEN 4. Sheets-Sheet 2 Filed March 13, 1939 -Aug. 12, 194.1. :ETERSEN I 2,252,520

METHOD AND APPARATUS FOR TREATING GARBAGE AND THE LIKE WASTE MATERIALS Filed March 13, 1939 4 Sheets-Sheet 3 Aug. 12', 1941. K. PETERSEN 2,252,520

AND THE LIKE WASTE MATERIALS Filed March is, 1939 METHOD AND APPARATUS FOR TREATING GARBAGE 4 Sheets-Sheet 4 Patented Aug. 12, 1941 METHOD AND APPARATUS FOR TREATING GARBAGE AND THE LIKE WASTE M'ATE- RJALS IjiaiPetersen, Soborg, near Copenhagen, Denmark Application March 13, 1939, Serial No. 261,631 In Great Britain March 23, 1938 Claims. (01. ss-9) The present invention relates to improvements in methods for treating garbage and the like waste materials which comprises subjecting the materials to a turning over, intermixing and grinding in one or more revolving compartments.

The invention relates also to improvements in improved method comprising an improved grind ing step in which an exhausting grinding is 'effected.

Another object of the invention is to provide apparatus which is better suited for treating garbage and the like waste materials. I

A further object of the invention is to provide adjustable means for transferring the com: ponents of the materials being treated and being not sufiiciently ground and/or non-grindable from one grinding chamber to thev following grinding chamber or for returning the components to the grinding chamber from which'they have been discharged. H A i A still further object of the invention is to provide adjustable means for discharging the components being diflicultly, grindable and/or non-grindable, from the apparatus while the same is in operation and in apparatus containing more revolving grinding chambers even during simultaneous supply of raw material.

A clear conception of the improvements according to the invention may be had by the following description providing a detailed explanation of the invention with reference to the accompanying drawings illustrating by way of example various preferred embodiments of apparatus and wherein:

Figure 1 is in its upper half a side view and in its lower half a longitudinal section on line I-,-- I of Figure 2 of one embodiment. V

Figure 2 is a cross-sectional view of the same on line IIII of Figure 1. 1

Figure 3 is a partly diagrammatic sectional view of a detail on line III-III of Figure 2.

Figure 4 is a cross-sectional View of another embodiment.

Figure 5 is a partial sectional view on an enlarged scale of the shaft of the adjustable member of the passage of the elevating device,

Figure 6 is a sectional view on line VI--VI of Figure 5.

Figure '7 is a cross-sectional view of. a further embodiment.

Figure 8 is a longitudinal sectional view of the similar manner as the elevating device 27.

rear-end portion of a still further embodiment.

Figure 9 is a cross-sectional .view of the same on line IXIX of Figure 8.

The apparatus shown in Figures 1 to 3 comprises a rotatable grinding drum having two end plates l and 3. A hollowtrunnion 5 is secured to the end plate I and journalled in a bearing 1. A toothed ring 9 is also secured to the end plate I and adapted to be driven by a pinion not shown. Connecting bracesor spider arms ll make the construction sufliciently rigid. Instead of the ring 9 a pulley may be secured to the end plate I so that the drum may be belt driven.

To the other end plate 3 there is secured a bearing ring I3 which rests on rollers ,l5, one of which is shown in Figure l. The. rollers l5 are journalled in bearings IT. The end plate 3 is provided with a central aperture l9 receiving the lower part of a stationary hopper 2 I.

The grinding drum is divided into two grinding chambers or compartments 23 and 25, respectively, by means of an elevating device 2! which is rigidly secured to double channel irons 29 equidistantly spaced circumferentially and secured at their endsto the end plates l and 3, respectively. Together with angularly bent grid bars 3| spaced and secured to the inner flanges of the said channel irons, the channel irons form the circumferential walls of eachgrinding chambers 23 and 25, the said walls thereby constituting a grid or coarse screen provided with stepped surfaces.

Both grinding chambers 23 and 25 are surrounded by conical screens or sieves 33 having a finer mesh than that of the grids or coarse screens forming the circumferential walls of the grinding idrum. Hereinafter they will be referred to as fine .sieves although they are only relatively fine, having for instance openings of about one centimeter in diameter. Bracing bars 35- are secured to the screens or sieves 33 as shown in Figurel.

At the outlet end of the: grinding chamber 25 there is arranged an elevating device 31 in a At the circumference of'each elevating device there are secured longitudinal lblades 39 being equidistantly spaced circumferentially and secured at one end to braces 4| connected with a collar" 43 encircling and securedto the front end of the fine sieve 33 surrounding the grinding chamber23.

'I'heelevati'ng device 21 being rigidly secured to the grinding drum, for instance welded thereto, and having a larger diameter than that of the grinding chambers consists of a casing formed by sidewalls 45 and 41 and a circumferential wall 49 secured to the side walls. By means of parallel transverse partitions 5| and 53 there are provided tube-like passages 55, of which four are shown in Figure 2. Through inlet openings formed by apertures 51 provided at the circumference of the side wall 45 the passages 55 communicate with the space inside the Through these outlet openings the passage 55 may communicate with the grinding chamber 23 or the grinding chamber 25. The inner portion of the passage 55 is limited by two abutting inclined plates 63 and 65. At the meeting edges of the inclined plates forming together a wedge a shaft 61 is journalled which carries a swingable member in the form of a fiat valve 59. The shaft 61 extends laterally to the axis of the grinding drum and transversely to the, longitudinal direction of the passage 55 to the circumference of the casing 21 where the said shaft is journalled in a bearing H. To the outer end of the shaft 61 there is secured an arm 13, as shown in Figure 1, having a stud moving in a slit '11. By moving the arm 13 the shaft 61 and the valve 69 connected thereto may be turned. To each of the inclined plates 63 and 65 there is secured an inclined plate 19 extending to the side wall 45 or 41 and connected therewith.

As appears from Figures 1 and 2 the passage 55 opens at a point spaced from the axis of the grinding drum, and the opposite outlet openings are positioned above the horizontal plane through the axis of the grinding drum when the inlet opening 51 is in the uppermost position. Moreover, the outlet openings of the passage are rearwardly disposed. inrelation to the inlet opening thereof with respect to the direction of rotation of the grinding drum indicated by an arrow a in Figure 2.

The elevating device 31 at the outlet end of the grinding chamber is constructed and arranged in the same way as the elevating device 21 with the exception that othermeans are used for turning the shafts of the flap valves 69. A slidable tube 8| extends through the hollow trunnion 5 of the grinding drum. To the inner end of this tube there-is secured a transversely arranged head 83 connected by links 85 with crank arms 81 on the shafts of the flap valves 69. A non-displaceable bar 89, upon which the tube 8| may slide, extends through the same. The outer end of the bar 89 is journalled in a bearing 9| supported by a bracket |0|. Moreover, the bar 89 is provided with a stop member I03 adapted to cooperate with a grooved collar I05 on the outer end of the tube 8| to limit the outward travel of the latter.

On the drawings no grinding bodies are shown although such are ordinarily used. However, they may be dispensed with when treating garbage and the like waste materials as it has been found that garbage is self-grinding Thus, in small plants where only small capacities are required the grinding bodies may be dispensed with. However, whenoperating on a large scale where high capacities are required a suitable number of grinding bodies, such as iron balls, is placed in the grinding chambers 23 and 25.

By means of a conveyor or similar supplying devices not shown on the drawings garbage is supplied to the grinding chamber 23 through the hopper 2| in such an amount as to obtain a suitable filling of the chamber. Prior to or after this action the grinding drum is started, the valves 69 of the elevating device 21 being in their left hand positions and the valves 69 of the elevating device 31 being in their right hand positions. During the rotation of the grinding drum, the material supplied is subjected to a turning over and mixing action simultaneously with a grinding action, the stepped surfaces .formed by the grid bars 3| promoting and enhancing the said actions. The material being able to pass the grids formed by the grid bars -3| falls down upon the fine conical sieve 33.

Owing to the inclination of the sieve the material is advanced on the inner surface during the sifting action. By means of the guiding blades 59 the non-siftable material is passed into the passages 55 through the inlet openings 57 when the openings are in their lower position. As the valves 69 are adjusted as mentioned above the non-siftable material will be discharged from the passages 55 during the rotation of the grindin'g drum through the outlet openings of the side walls 41 opposite to the outlet openings 6|. Thus, the non-siftable material will be transferred to the grinding chamber 25. Owing to the position of the outlet openings a degree of charging of the grinding chamber 23 above 50% maybe used, and during the rotation of the drum no substantial amount of the material present in the grinding chamber 23 will pass into the passages 55 through the outlet openings 6| when the openings are in their lower position. The large filling degree or degree of charging is of material importance when grinding garbage for the purpose of converting the garbage into a substantially homogeneous, granular and fibrous mass.

As the valves 69 of the elevating device 31 are in the position shown in dotted lines in Figure 1 the material being not able to pass the sieve 33 surrounding the grinding chamber 25, is returned to the said chamber.

In contradistinction to the usual grinding methods, in which the whole amount of starting material treated is reduced to the desired size of particles two products are formed during the grinding of garbage, namely the substantially homogeneous, granular and fibrous mass referred to above and constituting the product aimed at, and a waste or remnant consisting of the non-grindable and difiicultly grindable components of the garbage. The coarser parts of the said waste which can not be ground or only be ground with difiiculty so as not being able to pass the spaces of the grid bars 3| of the grinding chamber 23, are retained in the said chamber, while the less coarse parts of the waste being able to pass the grid bars 3| are transferred to the grinding chamber 25 and when leaving the same returned thereto by means of the elevating device 31.

Therefore, when the apparatus has beenin operation for a certain time with continuous supply of garbage through the hopper 2|, the waste or remnant will accumulate in the grinding chamber 23, whereas an increasing amount of waste or remnant will be present in the grinding chamber 25 so that the useful effect of the apparatus will by and by he decreased. After a certain period of operation depending on the nature of the waste material to be treated the apparatus is stopped. By means of the arms 13 the valves d9 of the elevating device 21 are swung so as to engage the sidewall 41 as shown in dot and dash lines in Figure 1. Then the apparatus is started again and a decreased amount of waste material is supplied through the hopper 2|. The nonsiftable material is now returned to the grinding chamber 23, while an exhausting grinding step is effected in the grinding chamber 25, i. e. a grinding step in which grindingis effectedwithout supply of material and continued until the said grinding chamber substantially only contains non-grindable and particularly difiicultly grindable materials (waste or remnants). Having finished the exhausting grinding step the valves 69 of the elevating device 31 are shifted to the position shown in dotand das'h lines in ing drum. Thereupon the valves 69 of the elevating device 31 are shifted again, sothat nonsiftable materials may be returned to the'grind ing chamber 25, whereupon the apparatus is stopped and the valves "69 of the elevating device 21 are returned to the position shownin dotted lines in Figure 1 so that the 'non-siftablematerials are transferred to the grinding chamber 25. Then the apparatus is started again and the amount of raw material supplied is increased to its normal rate. r a

An exhausting grinding step may be efiected in a grinding chamber 23 substantially inthe same manner as described above in connection with the grinding chamber 25, the supply of raw material being, however, completely stopped.

The mode of operation described above is only an example and may be modified in several manners. Thus, the exhausting grinding step may be effected in both of the grinding chambers 23 and 25 independent of the position of the valves 69 of the elevating device 21 when the supply of raw material is interrupted. Moreover, according to the grinding degree desired and the nature of the waste material to be treated some of the valves 69 of the elevating device 21 may be adjusted for transferring the non-siftable materials to the grinding chamber 25 and other of the said valves of the said elevating device may be adjusted for returning the non-siftable materials to the grinding chamber 23. 1

By means of the blades 39 the material passing the fine screens or sieves 33 may be carried to a conveying device known per se, for instance a belt conveyor, which is not. shown on the drawings.

In the elevating devices 21 and 31 of Fig. 4 a circumferential part of the side wall is cut away so as to form a helical inlet opening ID! the access of the material on the fine sieves 33 to the passages being thereby facilitated.

Moreover, the outer ends of the shafts 61 are accommodated in pockets IE9 at the circumference of the grinding drum, as shown in Figures 5 and 6. The outer end of each shaft 6! is journalled in a bearing HI secured to the outer wall H3 of the pocket Hi9. An arm or handle lever H5 is secured to the shaft 61. Thus by rocking the arm the valve 69 may be adjusted into the desired position.

In the apparatus shown in Figure '7 the passages 55' at their inlet ends follow a path substantially'tangential to the circumference of the grinding drum, the transport of the material through the said passages being thereby facilitated. Moreover, a circumferential part of the side wall 451s cut away so as to facilitate the acces's of the material on the fine sieves 33 to the passages 55 The apparatus shown in FiguresSandQismainly constructed in the same manner as the apparatus shown in Figure 1. It only departs therefrom by the interior construction of the elevating devices 2'! and 31, respectively, and by the fact that the spaces between the grid bars 3| of the grinding chamber 25 are smallerthan those of the grid bars of the grinding chamber 23.

In the elevating device 21 the outlet openings 6|? are centrally arranged. At the said outlet openings there is arranged a swingable conical member 69 which is supported by a shaft 6i rotatably' mounted in bearings lli. To the outer end of the said shaft there is secured a handle I I9. Vvhen turning said handle through an angle of the conical member 69 'is turned to the positionindicated by dotted lines in Figure 8. Also the elevating device 31 is provided with central-outlet openings fil but instead of ,a conical member an inclined plate 69* is arranged at the outlet openings, said plate being secured to a shaft l2l extending through the hollow trunnion 5 of theapparatusj When turning the shaft l2l through an angle of 180 the plate 69 will be turned' into' the position indicated by the dotted'line 'in Figure 8.

For transferring the material supplied to the elevating devices 21 and 31, respectively, through the inlet openings 51 to the conical member and the inclined plate, respectively, blades I23 are provided in'the'said devices, These blades are shown inFigure 9.

I-laving thus fully described my invention I claim as new and desire to secure by Letters Patent:

1. A'method of treating garbage and the like waste materials, which consists in subjecting the materials to a turning over, intermixing and grinding in revolving compartments forming success ve communicating grinding steps, removing the suff ciently groundmaterials from the individual steps byscreening, transferring the insufliciently ground-and non-grindable materials from one grinding step to the following grinding step, returning the insumciently ground and non-grindable materials from the said grinding steptothe same, continuing this mode of operation until the grinding effect is materially re-- duced due to the increasing amounts of the difficultly-grindable and non-grindable materials in the grinding compartments, then returning the said materials from the firstmentioned grinding step to the saine and continuing the return of the said materials from the following grinding step to the same thereby effecting an exhausting grinding in the said step, discharging the remnants therefrom and finally continuing the firstmentioned mode of operation.

'2. In an apparatus'for treating garbage and the like waste materials, a rotary grinding chamber the circumferential walls of which are provided with apertures,a s'creensurrounding the grinding chamber and adapted to advance the materials on the screening surface in the longitudinal direction of the apparatus, a rotary casing closing the outlet end of the grinding chamber" and provided with circumferential inlet openings communicating with the interior of the screen and opposite outlet openings spaced from the axis of the grinding chamber and communicating with the interior and the exterior of the grinding chamber, respectively, a plurality of passages within the said casing each connecting an inlet opening of the casing with two opposite outlet openings thereof, inclined plates limiting the inner nds of the passages, a swingable flap valve arranged at the meeting edges of the inclined plates and adapted to deliver the materials supplied to the said casing by the said screen to either of the opposite outlet openings the position of the said flap valve determining to which of the outlet openings the materials are delivered, and a shaft secured to the said flap valve and adapted to be operated from the outside of the grinding chamber.

3. Apparatus as claimed in claim 2, in which the shaft secured to the flap valve extends laterally to the axis of the grinding chamber and to the circumferential part of the rotary casing.

4. In an apparatus for treating garbage and the like waste materials, a rotary grinding chamber, a plurality of apertures in the circumferential walls of the said chamber through which apertures the ground material leaves the grinding chamber, a screen surrounding the grinding chamber and adapted to advance the materials on the screening surface in the longitudinal direction of the apparatus, a casing secured to the grinding chamber and rotating therewith, circumferential inlet openings in the said casing, the said openings communicating with the interior of the screen, pairs of outlet openings in the said casing, one outlet opening of each pair communicating with the interior of the grinding chamber while the other outlet opening of the same pair opens to the exterior of the grinding chamber, each pair of outlet openings being spaced from the axis of the rotary grinding chamber and so arranged as to be in a position above the horizontal line through the axis of the grinding chamber when the corresponding inlet opening is in its uppermost position, a plurality of passages within the said casing each connecting an inlet opening of the casing with one pair of outlet openings thereof, adjustable means arranged within each passage and adapted to deliver the materials supplied to the said passage by the said screen to either of the outlet openings in a pair, the position of the adjustable means determining to which of the outlet openings the materials are delivered, and means adapted to control the said adjustable means and ararnged to be operated from the outside of the casing.

5. Apparatus as claimed in claim 4, in which each 'pair of outlet openings is rearwardly displaced with respect to the direction of rotation of the grinding chamber in relation to the corresponding inlet opening.

6. Apparatus for treating garbage and the like waste materials comprising in combination, a rotary grinding chamber having a plurality of relatively large apertures in the circumferential wall thereof through which apertures the ground material leaves the grinding chamber, a screen surrounding the grinding chamber and adapted to advance the materials on the screening surface in the longitudinal direction of the apparatus, an elevating device secured to the grinding chamber and rotating therewith,'.said elevating device having inlet openings therein communicating with the interior of the screen and at least one pair of outlet openings, one outlet opening of each pair communicating with the interior of the grinding chamber while the other outlet opening of the same pair opens to the exterior of said chamber, adjustable means arranged within and rotating with the elevating device and adapted to deliver the materials supplied to said device by said screen to either of the outlet openings, the position of said adjustable means determining to which of the outlet openings the materials are delivered, and means adapted to control said adjustable means and arranged to be operated from the outside of the elevating device.

'7. Apparatus for treating garbage and the like waste materials comprising in combination, a rotary grinding chamber having a plurality of relatively large apertures in the circumferential wall thereof through which apertures the ground materialleaves the grinding chamber, a screen surrounding the grinding chamber and adapted to advance the materials on the screening surface in the longitudinal direction of the apparatus, an elevating device secured to the grinding chamber and rotating therewith, said device having inlet openings therein communicating with the interior of the screen and at least one pair of outlet openings, one outlet opening of each pair communicating with the interior of the grinding chamber while the other outlet opening of the same pair opens to the exterior of the said chamber, a shiftable member arranged within and revolving with the elevating device and adapted to deliver the materials supplied to said device by said screen to either of the outlet openings and the position of said members determining to which of the outlet openings the materials are delivered, and a shaft secured to said member arranged to be operated from the outside of the elevating device.

8. Apparatus for treating garbage and the like waste materials comprising in combination, a rotary grinding chamber having a plurality of relatively large apertures in the circumferential wall thereof through which apertures the ground material leaves the grinding chamber, a screen surrounding the grinding chamber and adapted to advance the materials on the screening surface in the longitudinal direction of the apparatus, an elevating device secured to the grinding chamber and rotating therewith, said elevating device having inlet openings therein communicating with the interior of the screen and at least one pair of outlet openings, one outlet opening of each pair communicating with the interior of the grinding chamber while the other outlet opening of the same pair opens to the exterior of the said chamber, a swingable flap valve arranged within and revolving with the elevating device and adapted to deliver the materials supplied to said elevating device by the screen to either of the outlet openings and the position of said flap valve determining to which of the outlet openings the materials are delivered, and a shaft secured to said flap valve arranged to be operated from the outside of the elevating device.

9. In a method of treating garbage and the like waste materials which consists in, turning over intermixing and grinding the materials in a revolving compartment, simultaneously subjecting the ground materials to a coarse screening perpendicular to the axis of rotation of the compartment, separating the fine and sufficiently ground components by a further and finer screening, returning the insufficiently ground diflicultly grindable and non-grindable components to the revolving compartment,continuing the grinding and returning operations until the material returned consists only of difiicultly grindable and non-grindable components, and mechanically discharging said components from the revolving compartment during the rotation thereof.

10. In an apparatus for treating garbage and the like waste materials, a rotary grinding chamber having a plurality of apertures in the circumferential wall thereof through which apertures the ground material leaves the grinding chamber, a screen surrounding the grinding chamber and adapted to advance the materials on the screening surface in the longitudinal direction of the apparatus, a casing secured to the grinding chamber and rotating therewith and having at least one circumferential inlet opening communicating with the interior of the screen, said casing having at least one pair of outlet openings with one outlet opening of each pair communicating with the interior of the grinding chamber while the other outlet opening of the same pair opens to the exterior of the grinding chamber, said casing having at least one passage connecting an inlet opening of the casing with one pair of outlet openings thereof, adjustable means arranged within each passage and adapted to deliver the materials supplied to said passage by said screen to either of the outlet openings in a pair, the position of the adjustable means do. termining to which of the outlet openings the materials are delivered, and means adapted to control said adjustable means arranged to be operated from the outside of the casing.

KAI PETERSEN. 

